Jacob & Marretje (Hopper) Ackerman in NJ

Jacob removed to Maryland after divorcing (1840's) his wife Marretje Hopper. Marretje remarried to John Hessel Doremus (1840's)and died 3/3/1853. I am interested in locating her burial place. Also that of her son Andrew Hopper Ackerman d7/2/1863, her grandsons Nelson Lewis Ackerman and Albert H. Ackerman, and her 2nd husband John Hessel Doremus. Also would like burial information on Dora Ackerman and her husband William Willis.